The present invention relates to an improved processor for photosensitive material wherein a plurality of operating conditions are sensed and signals are provided to an operator in response to detecting a failure in the operating conditions.
U.S Pat. No. 4,994,840, issued Feb. 19, 1991 in the names of D. O. Hall and B. R. Muller relates to an apparatus for processing a photosensitive material, such as a sheet of x-ray film. The apparatus of this patent has a processing unit with a vessel for retaining a processing fluid. Submerged in the processing fluid of the vessel is a processing device having a chamber through which the film travels during processing. Apparatus of this kind can be manufactured and sold at a relatively low cost. While low cost processors are desirable in many applications, the need to minimize manufacturing costs has limited the application of some features and devices from such processors. For example, low-cost film processors may have no devices for detection of error conditions, such as by failed parts of the apparatus. This makes it difficult for the processor operator to determine the cause of a failure and complicates service of such processors.
U.S. Pat. No. 4,994,837 issued Feb. 19, 1991 in the names of J. T. Samuels and R. D. Ellsworth for a processor with temperature responsive film transport lockout. This patent discloses a more expensive film processor incorporating a microcomputer coupled to sensors of various kinds for detecting operating conditions and to apparatus controlled by the microcomputer in response to detection of certain conditions. By incorporating microprocessors into low-cost processors, it is possible to monitor various systems or subsystems in the processor to detect error conditions. However, it is expensive to use a plurality of indicator lamps with each lamp being dedicated to indicate one specific error that has been detected. While such may be acceptable for more expensive processors, it is very desirable to reduce the number of indicator lamps or other signalling devices used for signalling the operator when each of a plurality of error conditions exist.